Junkbox Engineering: Working in 2D and 3D
What kind of thinking were these NASA scientists and engineers engaged? What was the problem? How did they work to solve that problem?
Science and Engineering
Most folks in science describe how they think by describing the scientific method. In a classic sense, the scientific method recapitulates the process a scientist uses to find out about the natural world. Although there are variations in the steps to this process, the most common elements in the sequence are:
Observe phenomena
Define or pose a question
Explore the work of others
Hypothesize an answer to the question
Test the hypothesis by performing an experiment or test
Collect and analyze data
Draw conclusions by explaining how the data supports or refutes the hypothesis
Communicate results in such a way that the experimental process could be replicated by another scientist
Scientists are interested in natural laws of physics, chemistry, biology, and earth and space sciences. Engineers, by contrast, think somewhat differently that scientists. One set of processes that NASA uses to describe the work of the Engineer is as follows:
Identify the problem
Identify criteria and constraints
Brainstorm possible solutions
Generate ideas
Explore possibilities
Select an approach
Build a model or prototype
Refine the design
For the Apollo engineers, their background in science and mathematics was key to helping them solve the problem. They were motivated by a practical problem and then had to pursue a solution given what they had on hand.
Crawling into an Engineer's Skin
Let's recreate some of that same way of thinking by exploring a problem teaching technology. Most people have heard of 3D printers and some know about laser engravers, CNC machines and plotters. These are modern marvels that can take ideas and make them into actual working models by either melting plastic in incremental layers to sculpt an object or to tear away at a solid object to create a 3D image or carving. The technology that underpins these machines requires an understanding of programming, interfacing from a computer to the machine, driving motors on a machine, the practical aspects of moving motors in 3 dimensions, and the actual sculpting or carving tool such as plastic melter, a laser, or a router blade.
A CNC Carving machine
These platforms move a router head in 3 dimensions to carve intricate patterns that are
sent from plans drawn on a computer
Where do we start learning about all of these things? We can buy a 3D printer and learn how to operate it. We can have someone show us how a CNC machine works or watch a video of a plotter or engraving machine. These give us a sense of the application of the technology and its utility, but very little of the both theoretical and practical aspects of the building blocks of that technology. The purpose of this segment is to give students an opportunity to understand the bones of this family of technologies such that when the machine moves left, down and then the laser fires, we know how that operation was accomplished. Because we want to explore the building blocks of the technology, we will look at mechanics, electronics, software, and interfaces. approaching everything, like the Apollo astronauts, with the delimitations of the classroom: Limited time, limited resources, and a limited capacity to "know everything" before we dive into teaching a unit. Sometimes, like the astronauts, we just have to explore and get our hands into the box of junk.
The Junk Box Engineering: Working in 2D and 3D
There are a number of explorations that are suggested in this unit. Any or all can be considered for a workshop of for regular classroom instruction. There are a few tools and specialized materials required throughout, but care has been taken to keep the overall cost and number of actual parts to a minimum. Some of explorations are better suited to small group instruction or club activities.
(UNDER CONSTRUCTION. THOSE UNDERLINED ACTIVE)
Soldering Practice
An overview of mechanics, electronics, and software systems (MESS)
Control Systems
Clock circuits
R/C variables
Meter/Code for resistance
CMOS sequencer
Actuators and Interfaces
Actuator motor
Stepper motors/screw
Transistor driver/switch
Motors
Motor testing
Reading a meter
1D, 2D and 3D Systems
2D Design
Printer Assemblies
3D Printing
CNC Machines